OmniSwitch os6900, Network Configuration Manual, Page: 657 / 942

Configuring QoS Creating Policies
OmniSwitch AOS Release 7 Network Configuration Guide June 2013 page 25-49
Note. If qos disable is entered, the rule is not used to classify traffic even if the rule is enabled. For more
information about enabling/disabling QoS globally, see “Enabling/Disabling QoS” on page 25-39 .
Rule Precedence
The switch attempts to classify flows coming into the switch according to policy precedence. Only the rule
with the highest precedence is applied to the flow. This is true even if the flow matches more than one
rule.
Precedence is particularly important for Access Control Lists (ACLs). For more details about precedence
and examples for using precedence, see
Chapter 25, “Configuring QoS.”
How Precedence is Determined
When there is a conflict between rules, precedence is determined using one of the following methods:
•
Precedence value —Each policy has a precedence value. The value is user-configured through the
policy rule command in the range from 0 (lowest) to 65535 (highest). (The range 30000 to 65535 is
typically reserved for PolicyView.) By default, a policy rule has a precedence of 0.
•
Configured rule order —If a flow matches more than one rule and both rules have the same
precedence value, the rule that was configured first in the list takes precedence.
Specifying Precedence for a Particular Rule
To specify a precedence value for a particular rule, use the policy rule command with the precedence
keyword. For example:
-> policy rule r1 precedence 200 condition c1 action a1
Saving Rules
The save option marks the policy rule so that the rule is captured in an ASCII text file (using the
configuration snapshot command) and saved to the working directory (using the issu slot command). By
default, rules are saved.
If the save option is removed from a rule, the qos apply command activates the rule for the current
session, but the rule is not saved over a reboot. Typically, the no save option is used for temporary
policies that you do not want saved in the switch configuration file.
To remove the save option from a policy rule, use no with the save keyword. For example:
-> policy rule rule5 no save
To reconfigure the rule as saved, use the policy rule command with the save option. For example:
-> policy rule rule5 save
For more information about the configuration snapshot , write memory , and copy running-config
working commands, see the OmniSwitch AOS Release 7 Switch Management Guide and the OmniSwitch
CLI Reference Guide.
For more information about applying rules, see “Applying the Configuration” on page 25-71 .